How to Read Degrees Percentage and mm/m on UNI-T LM320E Malaysia
How to Read Degrees Percentage and mm/m on UNI-T LM320E Malaysia
Content
Published: 3 October 2026
The UNI-T LM320E Digital Angle Meter can display a measured slope or angle in several units.
These include:
Degrees
Percentage
mm/m
in/ft
Each unit describes the same physical inclination in a different way.
The correct unit depends on the project drawing, installation specification and working practice.
Selecting the wrong unit can cause a serious installation error even when the number on the LM320E display appears stable.
What Do the LM320E Measurement Units Mean?
The LM320E does not perform four different types of angle measurement.
It measures the inclination of the instrument and converts that result into different units.
For example, the same slope may be shown as:
An angle in degrees
A rise or fall in percentage
A vertical change in millimetres per metre
A rise or fall in inches per foot
The user should confirm the required unit before adjusting or accepting the installation.
What Does the Degree Reading Mean?
Degrees describe the angle between the measured surface and a reference position.
A reading of 0° generally represents a horizontal position.
A reading of 90° represents a vertical position.
Other readings show how far the surface is inclined between these reference positions.
Degree measurement is commonly used for:
Machinery components
Steel frames
Fabricated brackets
Inclined panels
Roof structures
Adjustable supports
General angle comparison
The LM320E has a 4 × 90° measurement range, allowing it to display the instrument’s orientation through different positions.
When Should You Use Degrees?
Use degrees when:
The drawing states an angle in degrees
The component must be installed at a specified angle
Two surfaces need to be compared
An existing angle needs to be copied
A bracket or frame has an angular requirement
The customer communicates the requirement in degrees
Do not convert the requirement to percentage or mm/m unless necessary.
Working directly in the specified unit reduces the risk of conversion errors.
What Does Percentage Slope Mean?
Percentage slope describes the amount of rise or fall compared with the horizontal distance.
The basic relationship is:
Percentage slope = Vertical change Ă· Horizontal distance Ă— 100
For example, a 2% slope means that the surface rises or falls by 2 units for every 100 units of horizontal distance.
This may also be understood as:
2 mm over 100 mm
20 mm over 1,000 mm
2 cm over 1 metre
The direction of the slope must still be checked.
A 2% value alone does not explain whether the surface is rising or falling in the intended direction.
Where Is Percentage Slope Used?
Percentage slope may be used for:
Drainage installation
Pipework
Floor falls
Ramps
Roof drainage
Cable trays
Civil construction
Access routes
Water-flow applications
The correct percentage should come from the approved drawing or project specification.
The installer should not choose a slope based only on general experience.
What Does mm/m Mean?
The mm/m unit describes how many millimetres a surface rises or falls over one metre of horizontal distance.
For example:
1 mm/m means a 1 mm change over 1 metre
5 mm/m means a 5 mm change over 1 metre
10 mm/m means a 10 mm change over 1 metre
20 mm/m means a 20 mm change over 1 metre
This unit can be easier to understand on site because it directly connects the slope to a one-metre distance.
Where Is mm/m Useful?
The mm/m display may be suitable for:
Pipe installation
Machine-base checking
Steel-support installation
Floor-slope inspection
Drainage work
Cable-tray installation
Long brackets
Fabricated frames
It is useful when the drawing or method statement specifies the permitted change in millimetres over a known distance.
The user must still confirm whether the stated distance is horizontal distance or actual surface length.
What Does in/ft Mean?
The in/ft unit describes the rise or fall in inches over one foot.
It may be used when:
The drawing uses imperial measurements
Imported equipment has an imperial installation specification
A contractor works in inches and feet
A slope requirement is stated per foot
Malaysian projects generally use metric measurements, but some imported machinery, technical manuals and customer specifications may still use imperial units.
Do not switch between metric and imperial units without checking the conversion carefully.
Degrees and Percentage Are Not the Same
A common mistake is to assume that one degree equals one percent.
This is incorrect.
Degrees represent an angle.
Percentage represents the ratio of vertical change to horizontal distance.
For smaller slopes, the numbers may appear relatively close, but they are not interchangeable.
Approximate examples include:
1° is approximately 1.75%
2° is approximately 3.49%
3° is approximately 5.24%
5° is approximately 8.75%
10° is approximately 17.63%
These values are approximate.
For installation acceptance, use the unit stated in the specification instead of estimating the conversion mentally.
Percentage and mm/m Conversion
Percentage and mm/m are directly related.
A slope of 1% equals 10 mm/m.
A slope of 2% equals 20 mm/m.
A slope of 3% equals 30 mm/m.
A slope of 5% equals 50 mm/m.
The basic relationship is:
mm/m = Percentage Ă— 10
Percentage = mm/m Ă· 10
For example, if a drawing specifies 15 mm/m:
15 Ă· 10 = 1.5%
The required slope is therefore 1.5%.
Why Can the Same Surface Show Different Numbers?
The LM320E may show different numerical values when the user changes the measurement unit.
This does not necessarily mean that the angle has changed.
For example, one surface may be displayed as:
Approximately 1°
Approximately 1.75%
Approximately 17.5 mm/m
These values describe approximately the same physical slope.
The number changes because the selected unit changes.
Always check the unit symbol shown on the display before recording the result.
Example: Setting a 2% Pipe Slope
Assume a project drawing requires a pipe slope of 2%.
A 2% slope is equivalent to:
20 mm of vertical change over 1 metre
40 mm of vertical change over 2 metres
100 mm of vertical change over 5 metres
The installer may set the LM320E to percentage mode and adjust the pipe until the required reading is obtained.
Before accepting the result:
Confirm the intended slope direction
Check that the meter is aligned with the pipe
Make sure the meter does not rock
Measure at several positions
Verify the total rise or fall over the installation length
Recheck after tightening the supports
A local angle reading should be compared with the overall installation requirement.
Example: Checking a Machine Base
A machine installer may need to check whether a base is level or within a permitted slope.
The LM320E can be placed on a suitable machined or reference surface.
The user may work in:
Degrees for general angle checking
Percentage when the tolerance is specified as a ratio
mm/m when the permissible change is stated over one metre
The selected surface must represent the machine base correctly.
Paint buildup, dirt, burrs, damage and uneven contact can affect the reading.
For precision machinery installation, the LM320E may not replace a precision machinist level or approved alignment system.
Example: Installing Repeated Brackets
When several brackets must follow the same angle, relative measurement may be more convenient than converting every reading.
A possible method is:
Position the first bracket at the approved angle.
Place the LM320E on the reference surface.
Confirm the result using the specified unit.
Set the approved position as the relative reference.
Move the instrument to the next bracket.
Adjust the bracket until it matches the reference.
Repeat the measurement before final tightening.
Inspect all brackets after installation.
The first bracket must be correct because every later comparison depends on that reference.
Absolute Mode vs Relative Mode
Absolute mode shows the measured angle according to the instrument’s standard reference.
Relative mode allows the user to assign a new zero position.
Use absolute mode when:
Checking horizontal level
Checking vertical position
Following an angle stated in a drawing
Recording an actual slope value
Comparing the result with a specification
Use relative mode when:
Copying an existing angle
Comparing two surfaces
Installing repeated components
Working from an approved reference
Checking deviation from a selected position
The display should be checked carefully because a relative reading may look acceptable even when the original reference was incorrect.
Why Measuring Direction Matters
An instrument may show the correct numerical slope while the component falls in the wrong direction.
This is especially important for:
Drainage pipes
Roofs
Floors
Gutters
Cable routes
Fluid-transfer systems
Before accepting the result, identify:
The high point
The low point
The intended flow direction
The measurement direction
The reference position
Marking the required direction on the drawing or component can help prevent installation mistakes.
Why Measurement Length Matters
A slope value describes a relationship over distance.
If the LM320E is placed on a very short section, the local reading may not represent the entire installation.
A long pipe or frame may contain:
Local bending
Uneven supports
Joint movement
Surface irregularities
Different slopes along its length
Take readings at several positions and compare them with the total rise or fall over the full working distance.
A correct reading at one point does not guarantee that the entire structure follows the same slope.
Common Unit-Selection Mistakes
Common mistakes include:
Reading degrees when the drawing specifies percentage
Treating 2° as 2%
Confusing 10 mm/m with 10%
Using imperial units for a metric drawing
Ignoring the positive or negative direction
Changing units during a series of inspections
Recording the number without recording the unit
Using relative mode when an absolute result is required
Estimating conversions without checking them
Measuring only one short section of a long installation
Every recorded result should include both the value and its unit.
Writing “2” without stating degrees, percentage or mm/m is incomplete.
How to Record an LM320E Reading
A useful site record may include:
Instrument model
Measurement location
Date and time
Selected unit
Displayed result
Measurement direction
Absolute or relative mode
Surface condition
Operator name
Required tolerance
Pass or fail decision
For repeated inspections, mark the measurement position so that another operator can reproduce the test.
How to Improve Repeatability
Before taking the final reading:
Clean the contact surface.
Clean the magnetic base.
Confirm the correct unit.
Confirm absolute or relative mode.
Position the meter in the correct direction.
Allow the reading to stabilise.
Repeat the measurement.
Check another point on the component.
Compare the result with the drawing.
Record the unit together with the value.
If repeated measurements differ significantly, investigate the surface, positioning and measurement method before averaging the results.
When Is Another Instrument Required?
Another measuring instrument may be required when:
The permitted tolerance is very tight
The reference surface is too small
The component is strongly curved
Long-distance elevation must be established
Precision machine alignment is required
A certified survey result is needed
Outdoor levelling is required
The project specifies another measurement method
The LM320E is a practical digital angle meter, but instrument selection should always follow the application and required accuracy.
Who Should Understand the Different Units?
Correct unit selection is important for:
Mechanical contractors
Pipe installers
Steel fabricators
Building maintenance teams
Renovation contractors
Cabinet installers
Quality-control inspectors
Machinery installers
Technical students
Site supervisors
Companies in Selangor, Kuala Lumpur, Johor and Penang should confirm the required unit and installation tolerance before selecting or using the LM320E.
For application advice, send MTM Precision a photo of the measurement surface together with the required angle, slope unit and working distance.
MTM Precision Sdn Bhd
Showroom & Service Centre: No. 29-1 & 29-2, Jalan Bandar 18, Pusat Bandar Puchong, 47160 Puchong, Selangor, Malaysia
Tel: 03-8080 7172
WhatsApp: +6016-660 7346
Email: mtmpre@yahoo.com
Website: www.mtmpre.com.my
03 Oct 2026
